1. Field of the Invention
The present invention relates to a recording tape cartridge including a case within which is housed a single reel wound with a recording tape, such as a magnetic tape, mainly used as a recording and playback medium for computers and the like.
2. Description of the Related Art
Magnetic tape cartridges including a case within which is housed a single reel wound with a magnetic tape used as a recording and playback medium for computers and the like have conventionally been known. A leader member, such as a leader pin, a leader tape, or a leader block, is disposed at a leading end of the magnetic tape. A pull-out mechanism disposed at a drive device pulls out the leader member through an opening in the magnetic tape cartridge and winds the magnetic tape fixed to the leader member around a take-up reel of the drive device.
A reel gear is annularly disposed in a center of a bottom surface of the reel, which is exposed through an open hole that penetrates a bottom surface of the magnetic tape cartridge. A drive gear disposed at a rotating shaft of the drive device meshes with the reel gear, whereby the reel is rotatingly driven. Data can be recorded on the magnetic tape, and data recorded on the magnetic tape can be played back, by synchronously rotating the reel of the magnetic tape cartridge and the take-up reel of the drive device.
Such magnetic tape cartridges are ordinarily plurally housed and stored in a storage called a library device. Rear end sides of both side walls of a desired recording tape cartridge are gripped by a gripping mechanism disposed with a robotic hand and removed from respective storage portions of the library device. The recording tape cartridge is then loaded into one of plural drive devices, whereby data is recorded in the magnetic tape cartridge or data recorded in the magnetic tape cartridge is played back.
A card-type memory board, in which is stored various information such as the recording capacity and the recording format of the magnetic tape cartridge, is internally disposed in a rear wall side of each magnetic tape cartridge so that the magnetic tape cartridge removed from the library device is smoothly loaded into one drive device. It is possible to access (read and write) the memory board with electromagnetic waves in a non-contact mode. The various information stored in the memory board is non-contactingly read by a reading device disposed at the robotic hand and a reading/writing device disposed at the drive device. In this manner, a drive device capable of recording data in the magnetic tape cartridge or capable of playing back data recorded in the magnetic tape cartridge is identified in advance by a control device or the like of the library device, whereby there is no loss in the operation of the gripping mechanism such as the robotic hand.
A conventional magnetic tape cartridge 70 is shown in FIG. 6. The magnetic tape cartridge 70 includes an upper case and a lower case that are joined by screws being screwed therein from an underside. As is shown, screw bosses 80, 82, 84 and 86 are disposed for that purpose. A memory board M is disposed, at an inner side of a rear wall 72 (the direction of arrow P is the front wall) of the recording tape cartridge 70, with an orientation such that it slants at a predetermined angle in a vicinity of the screw boss 80. In other words, the memory board M is disposed at an elevation angle of 45° when seen in side view, so that the memory board M can be accessed from both (two directions) of a rear surface (rear wall 72) and an undersurface 74. Additionally, the memory board M is disposed in the vicinity of a joint portion, i.e., the screw boss 80, whose relatively high strength is secured, so that the position of the memory board M is not shifted even if the memory board M sustains impact resulting from the magnetic tape cartridge 70 being dropped or the like.
Therefore, a reading device 78 disposed at a robotic hand can appropriately access (transmit electromagnetic waves to and receive electromagnetic waves from) the memory board M from the rear surface (rear wall 72) of the magnetic tape cartridge 70, and a reading/writing device 76 disposed at a drive device can appropriately access (transmit electromagnetic waves to and receive electromagnetic waves from) the memory board M from the undersurface 74 side of the magnetic tape cartridge 70. It should be noted that the reading/writing device 76 is a device that not only reads information from the memory board M but also writes information thereto.
It is preferable to dispose the memory board M in this manner in the vicinity of the screw boss 80, which vicinity is a joint area between the upper case and the lower case, because positional shifting of the memory board M is deterred even if the memory board M sustains impact resulting from the magnetic tape cartridge 70 being dropped or the like. However, in order to ensure reliable access by the reading device 78 and the reading/writing device 76 with respect to the memory board M, it is necessary to precisely maintain the distance (a distance for transmitting and receiving electromagnetic waves) from the reading device 78 and the reading/writing device 76 to the memory board M. For this purpose, the memory board M must be precisely positioned in the case.